Brush-holder for dynamo-electric machines.



N0. 66I,538.- Patented Nov. [3. I900.

C.'W. KRAGH.

BRUSH HOLDER FOR D YNAMO ELECTRIC MACHINES. (Application filed Sept. 11.1899.

(No Model.)

WWW l 1 tUNrTnD STATES PATIENT @rrrch.

CHRISTIAN lV. KRAGH, OF MADISON, WISCONSIN, ASSIGNOR TO THE NORTHERNELECTRICAL MANUFACTURlNG COMPANY, OF SAME PLACE.

BRUSH-HOLDER FUR DYNAMQ-ELECTMG MACi-HNES.

SPECIFICATION forming part of Letters Patent No. 661,538, dated November13, 1900.

Application filed September 11, 1899. serial 1t 0. 730,059. the model.)

To all whom it 'mcty concern.-

Be it known that I, CHRISTIAN W. KRAGH, a citizen of the United States,residing at Madison, in the county of Dane and State of VViscousin, haveinvented a certain new and useful Improvement in Brush-Holders forDynamo-Electric Machines, of which the following is a specification.

My invention relates to brush-holders for dynamo-electric machines, andhas for its object to provide a new and improved brushholder of thisdescription.

My invention is illustrated in the accompanying drawings, wherein-Figure 1 is a side View of a brush-holder embodying my invention. Fig. 2is a plan view of the/device shown in Fig. 1. Fig. 3 is a sectional viewof a part of the brush-holder attached to the stud or bolt by means ofwhich the brush-holder is held in place.

Like lettersrefer to like parts throughout the several figures.

One of the objects of my invention is to provide a brush-holder whichwill elastically press the brush against the commutator.

The brush A, which makes contact with the commutatorof the machine, maybe made of any suitable material and is attached to the holding-piece B.The brush is preferably connected to the holding-piece in some suitablemanner, so as to avoid a sliding contact. As illustrated in thedrawings, two screws A A pass through the brush and clamp it firmly tothe holding-piece B. I prefer to provide an outer conducting-piece A thebrush being securely clamped between this piece and the end of theholding-piece B, so as to insure a good electrical contact between theparts. The holding-piece B may be made of any desired form and, asherein shown, is provided at its end with two branches B B, saidbranches being provided with openings for the supporting stud or bolt BThis bolt passes loosely through these openings, so that theholding-piece B is free to move about the bolt. Between the branches Bis an engaging part 0, which engages the supportingbolt B This engagingpart may be of any suitable construction and, as herein shown, consistsof a split collar, the split ends of which are connected by means of aclampingscrew C, so that the engaging part may be rigidlyclamped to thebolt 13*. It will be seen that by this construction the engaging part isadjustably clamped to its support. The holding-piece B is elasticallyconnected to the engaging part C. Any suitable means for this purposemay be used. As herein illustrated, this elastic connection is made bythe spring B which is attached at one end to the engaging part C, theother end engaging the holding-piece B. This spring passes between thebranches B, as shown. In order to compensate for the relative movementof the holding-piece B and the engaging part 0, I provide the springwith a slot B The end of this spring presses upon the upper face of theholding-piece B, and a screw B connects the spring and the holding-pieceB together. It will be seen that by this construction the spring and theholding-piece B are permitted to move relatively, the movement in onedirection being limited by the engagement of the screw B with the innerend of the slot B It will also be seen that by this construction thebrush is elastically pressed against the commutator and that the brushmay be controlled by adjusting the position of the engaging part C. Inorder to do away with the sliding contact between the holdingpiece B andthe supporting stud or bolt B I connect the engaging part 0 with theholdingpiece B by means of the contact-spring O Said contact springpasses between the branches B of the holding-piece, as shown, and hasits end connected to a cross-piece B, connecting said branches. Thiscontactspring permits the relative movement of the holding-piece B andthe engaging part 0, and yet provides a stationary contact between them.

In practice several of the brush-holders aregenerally connected to asingle supportingstud, and a series of these studs are used. It is ofcourse evident that the brush may be used in any desired manner, and Ido not limit myself in this particular. It will be seen that whenseveral brush-holders are attached to a single supporting-stud any oneof the brush-holders may be removed from the commutator by unclampingthe engaging part 0 and may then be moved to a position out of the way,so that any desired change or repair may be made while the machine is inoperation.

I have described in detail a particular construction embodying myinvention; but it is of course evident that this construction may bevaried in many particulars without departing from the spirit of myinvention, and I therefore do not limit myself to the constructionshown.

I claim 1. In a brush-holder for dynamo-electric machines, thecombination of a holding-piece to which the brush is attached, a supportupon which said holdingpiece is movably mounted, a flat spring attachedto said support and connected with said holding-piece by a slidingcontact and so as to elastically press the brush against the commutator,and a conductor fixedly attached to the support and to the holding-pieceso as to give a fixed connection around the connection between thesupport and holding-piece.

2. A brush-holder for dynamo-electric machines, comprising aholding-piece to which the brush is connected, said holding-pieceprovided with two branches and movably mounted upon a support, anengaging part between said branches, said engaging part securelyattached to said support, a spring connected with said engaging part andpass ing up between the branches of the holdingpiece, said springengaging the holding-piece on its upper face, so as to elastically pressthe brush against the commutator.

3. A brush-holder for dynamo-electric machines, comprising aholding-piece to which the brush is connected, said holding-pieceprovided with two branches and movably mounted upon a support, anengaging part between said branches, said engaging part securelyattached to said support, a spring connected with said engaging part andpassing up between the branches of the holdingpiece, said springengaging the holding-piece on its upper face, so as to elastically pressthe brush against the commutator, and acond uctor fixedly attached atone end to the hold ing-piece and at the other end to the engaging part.

CHRISTIAN \V. KRAGH.

Witnesses:

FRANK L. STAGG, AUGUST J. BUENZLI.

